


Girls Will Be Girls

by monsterfucker



Category: The 100 (TV)
Genre: F/F, Light Dom/sub, POV Bellamy Blake, Voyeurism, not quite incest but incesty vibes
Language: English
Status: Completed
Published: 2019-01-30
Updated: 2019-01-30
Packaged: 2019-10-17 11:21:27
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,701
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17559431
Author URL: https://archiveofourown.org/users/monsterfucker/pseuds/monsterfucker
Summary: For the prompt: Bellamy puts a teddy bear cam in Octavia's room because he suspects she's fooling around with her best friend Clarke. He thinks they are way too young to be doing that kind of thing, but he doesn't want to bring up the issue without proof. When he finally watches the feed, he's shocked by what he finds.





	Girls Will Be Girls

**Author's Note:**

> Weirdly this fic inspired an original (non-erotic) novel idea?? 
> 
> Heed the tags please.

Bellamy doesn’t usually have insomnia, but he must have had too much caffeine because tonight his brain just won’t shut off. It’s a Friday which means Clarke is sleeping over, and at least he doesn’t have work the next morning. He’s dwelling on all the errands he has to run tomorrow, when he hears a noise, what sounds like a shrill cry, pained enough that he’s bolting upright in bed. Then he hears giggling and shushing. He relaxes, can hear the barely audible tone of the TV in the living room. He put them to bed hours ago, but he guesses they’re finally old enough to sneak back out and watch a movie. He guarantees it was Octavia’s idea. Clarke is the sweetest, most well-behaved girl he’s ever met, and he hates that his sister is a bad influence on her. Honestly, he’s surprised Abby lets Clarke come over at all.  
  
More giggling and shushing follows, and he’s just about to go out there and tell them to get back to bed when he hears a new noise, one he couldn’t have possibly heard: a moan. Definitely from his sister, nearly identical to the sound she makes when he tells her to do the dishes before she can get on his laptop.   
  
He can’t not investigate this. As much as he’s afraid of what he might find, he gets out of bed and quietly opens his bedroom door. Two shushes come in quick succession, followed by the blip of the TV as it turns off. He makes his way to the bathroom, pretending he can’t see the huddled mass under a blanket on the floor of the living room. He’s about to enter the bathroom when he spots something else — clothes. Pajamas, pooled into little piles on either side of them. He doesn’t want to jump to conclusions. Doesn’t want to imagine they’re naked under the blanket, doing things to each other that would elicit moaning. There’s no way that can be happening. They’re only thirteen.   
  
Part of him wants to march into the living room and uncover them and tell them to get to bed, revoke Octavia’s laptop use for a week, and take Clarke home. But if they’re really fooling around, it would be humiliating for everyone involved. He wishes his mother weren’t dead — she’d know how to handle this. It’s not like they can get each other pregnant, he reasons. They’re the same age. They’re going through puberty. They love each other. Lying naked together on a floor, kissing maybe, touching each other — whatever they’re doing, it’s not the end of the world.  
  
Bellamy pushes into the bathroom, and by the time he comes out again, the girls have gone back to bed.

* * *

For the first time in Bellamy’s entire life, he’s grateful that Octavia refuses to part with her little kid toys. Her room is a mess despite how often he makes her clean it (always a half-assed job; she doesn’t even use her hands, just kicks stuff around until he can see the floor again), so when he buys a teddy bear cam, it looks right at home on her shelf of plushies. It’s Friday again, and in a couple hours he has to pick up Clarke and Octavia from Harper’s birthday party. Hopefully they’ll have worn themselves out bowling, and want to come home and go to bed. There’s no way in hell that’ll happen, but a much older brother with legal custody of his sister can dream.   
  
He sets up the app on his iPad. The teddy bear cam is trained on the bed, so it won’t work if they move to the living room again. But, he reasons, if they go to the living room again, he can catch them red-handed, and this time he’ll be prepared. He has a plan. It’ll be an uncomfortable conversation, but he has to be the adult here and deal with it.  
  
When he picks the girls up from the bowling alley, they’re scream-singing Taylor Swift and begging for him to take them out for ice cream. He let them stay out an hour later than he usually does, so it’s ten p.m., and he tells them all the ice cream places are closed.   
  
“Walmart!” Octavia says. “Let’s go to Walmart and get stuff to make cookies.”  
  
She’s getting a little too comfortable making demands, and he’s starting to worry that maybe Octavia has pressured Clarke into things she didn’t want to do, when Clarke says, “Ask nicely, O. Bellamy isn’t our butler.”  
  
“Thank you, Clarke,” Bellamy says.  
  
“Can we please go to Walmart and buy cookie supplies?” Octavia asks.  
  
He should say no. They don’t have time to make cookies before bed anyway. But he finds himself turning away from home, toward Walmart, telling himself they’ll be able to run themselves ragged in the store and maybe wind down a little from the party.  
  
The second they step inside, Octavia bolts toward the junior girls’ section and Clarke shoots him an apologetic glance before following, which leaves him to get a cart and pick everything out at the other side of the store. It strikes him, then, how much Clarke has grown in seemingly the blink of an eye, but it had to have been months. She wears a bra now, a B-cup if he had to guess, and mascara and lip gloss. Her shirts ride a little too low and a little too short. She’s only in eighth grade but she could pass for a high schooler. Meanwhile Octavia is still the wild string bean she’s always been, messy hair and big t-shirts, track pants. He took her bra shopping exactly once, and she hated it, and they got into a fight about it ("I don't  _want_ to have boobs!") but eventually she settled on a sports bra. He was hoping Clarke would convince her to take the boob enterprise more seriously.  
  
As he rolls the cart down the aisles, he’s grateful to have taken the detour — he didn’t realize how much stuff they were out of. When he’s done, the cart is half-full of produce and laundry detergent and the brand of pads Octavia likes (she’s too shy to tell him when they’re out, he has to check), as well as eggs and brown sugar and chocolate chips.   
  
He goes all around the store looking for them, expecting to find them in the toy aisle, but they must be too old for that now, so he looks in the junior’s section. They’re not there either. As he passes the lingerie aisle, he catches movement in his peripheral vision. He stops. At the end of the aisle, Octavia is quickly stepping away from Clarke, and both of them look down and away. Their lips are reddened. Clarke’s face and chest are flushed pink. He’s too shocked to say anything. Thankfully Octavia pops into a grin, pretending he hadn’t just caught his thirteen-year-old sister making out with her best friend in the lingerie aisle of a Walmart.   
  
“Did you get everything?” she asks. Clarke is staring at her phone, turned completely away from him.   
  
“Yeah,” he says. “Let’s go.”

* * *

It’s midnight when the cookies are finally done baking. Bellamy hasn’t left Clarke and Octavia alone for a single second since they got home, and now that he knows what’s going on, he can feel Octavia’s irritation toward him. She rolls her eyes and makes snippy comments at him that Clarke has to tell her to apologize for. The cookies come out underdone, and each of them only eats two, while Bellamy is left with a kitchen full of dirty dishes.   
  
“We’re going to go to bed,” Octavia says abruptly. She takes Clarke’s wrist and says, “Goodnight.”  
  
He hears the slam of her bedroom door and then silence, waits a beat in case she spots a teddy bear she doesn’t recognize and comes out accusing him of spying on them. But nothing happens, so he turns off all the lights and goes into his room and turns on his iPad.  
  
It was kind of a cheap cam, so he wasn’t expecting to see much, but the picture is clear: they’re standing, kissing, Octavia’s hands cupping Clarke’s chin. It’s one thing to suspect, and another to catch the aftermath, and still an entirely new thing to see the act itself. He can’t breathe. It’s not just that they’re kissing, it’s the way they’re kissing — hard and deep and possessive, the way Bellamy didn’t kiss anyone until he was seventeen, maybe older. He’d expected innocent fumbling, lips only, but Octavia’s tongue is firmly in Clarke’s mouth. She even bites Clarke’s lower lip between her teeth. He has no idea where she could have learned that.  
  
“Will you put them on?” Octavia asks. The iPad’s volume is on loud, and Bellamy nearly jumps out of his skin, scrambles to find a pair of headphones and plug them in. By the time he has them settled in his ears, Clarke is taking something out of Octavia’s hand.   
  
“You didn’t have to steal these,” Clarke says. “I could’ve bought them.”  
  
“Bellamy would’ve thrown a fit.”  
  
He can’t see what’s in Clarke’s hand but from context and size, he’s guessing it's a pair of underwear. Octavia sits on the bed, leans back on her palms and says, “Get undressed.”  
  
Clarke’s back is to the camera. She lifts her shirt over her head and drops it to the ground, then reaches behind her to undo her bra.  
  
Bellamy clicks off his iPad and throws it to the opposite end of the bed. He can’t watch his barely-teenage sister have sex. Then again, he thinks, if he’s going to confront her about this, he needs to know what to say. She gave Clarke a direct order, so they need to talk about consent. She stole a pair of underwear. They need to talk about that too. They probably need to talk about queerness. He’s always suspected that his sister was a lesbian, but he always thought that would be a conversation for another day. Another, older day, when she would maybe come out to him, and it would be a joyous, tearful thing, and he’d tell her how proud of her he was.   
  
That might still happen, but now it’ll be with the knowledge that his sister is some kind of gay sex demon at the age of thirteen.   
  
He picks up the iPad again. His hands are shaking as he unlocks it. The picture buffers for a second, and he immediately regrets looking. Clarke is completely naked, stepping into the stolen underwear. Octavia is fully dressed, looking up and down her body hungrily. Bellamy is grateful that Clarke’s back is still turned, and she’s in shadow. He can’t see anything, really —   
  
Until Octavia takes her by the hip and turns her around to look at her ass, and Bellamy is in full view of Clarke’s brand new teen girl tits. They’re small still, albeit bigger than all her friends’, pointed, soft pink nipples peaked in the chill of Octavia’s room, which always runs a few degrees lower than the rest of the house. He guesses she still has a lot of growing to do, and he’s really not looking forward to it. His cock twitches at the thought, and he is completely sure if someone is keeping score, he just got his ticket punched for hell.

“Lay down,” Octavia says. Clarke does what she’s told. Clarke always does what she’s told. God, he should have seen this coming.  
  
Octavia pulls something out of her bedside drawer — one of his neckties. The black tie he was looking for when he had to meet with a client last week, the one he wears with his grey suit. She’s gotta quit stealing shit.  
  
He thought Girl Scouts had had a great impact on her, but now he sees that he was wrong. She’s tying Clarke’s wrists to the headboard expertly, with all the confidence of a girl who has three badges in knot-tying.   
  
“Try to get out,” Octavia says.  
  
Clarke tugs at her restraints and shakes her head.  
  
“You know, last week you made a lot of noise. Almost got us caught. I think you need punished for that, don’t you?”  
  
Clarke shakes her head again, but the pout she’s putting on looks fake. He’s seen it when Abby says no to her about something. Her assent, the obvious playing-along, gives him only the slightest solace, which is immediately dampened when Octavia takes off her shirt. She’s wearing her sports bra, at least, which feels like a weird win right now. He braces himself for her nudity — he’s seen her naked a million times. He changed her diaper. He gave her baths until she was eight. Not a big deal.   
  
It feels like a slightly bigger deal when she slips off her boyshorts, crumples them into a ball, and forces them into Clarke’s mouth.  
  
“One noise from you and it’ll be worse,” Octavia says. “Nod if you understand.”  
  
Clarke nods.   
  
The next several minutes are spent with Octavia between Clarke’s legs, kissing her all over, paying special attention to her breasts. She’s saying things that the mic can’t pick up, but they sound like compliments. He catches the words “beautiful” and “think about you” and “taste so good.”  
  
When she reaches Clarke’s stolen underwear, she doesn’t take them off, just slides the crotch of the panties over and slips her middle finger inside. Clarke’s body jolts, but she doesn’t make a sound.   
  
“You’ve been such a good girl for me today,” Octavia says. “You wanna come?”  
  
Clarke nods emphatically.  
  
“You’re so hot, baby. It’s amazing I can ever keep my hands off you.”  
  
She had to have gotten into his vintage porn stash. It's the only explanation. PornHub porn wouldn't have taught her how to talk like that. He should have hidden his stuff better, but in his defense, he didn't think Octavia would snoop around while he wasn't home.   
  
Bellamy turns away when Octavia lowers her mouth to Clarke’s pussy and starts eating her out. He doesn’t flip off the iPad this time, but he does squeeze his eyes shut, which leaves him only with slick sounds and Clarke’s heavy breaths. It’s hard to believe this is happening right across the hall, this domination scenario straight out of Sluts of the Nile 5.   
  
He opens his eyes again when he hears the drawer shut and a buzzing sound. She has a vibrator in her hand, a thin pink thing. How long has she had that? Where did she get it? She probably stole it from the mall. He's never letting them go off on their own again.  
  
He closes out of the app and opens a browser to google what he should do, when he realizes there’s no way to google “my daughter is having BDSM sex with her best friend what should I do?” For a second, with the app closed and not being unable to hear anything coming from the bedroom, he convinces himself it’s not happening. It never happened, and he never knew about it, and so he doesn’t have to do anything at all.   
  
Against his own will, his hands find the cam app again. When the picture returns, Octavia is between Clarke’s legs, a vibrator pressed against Clarke’s clit with two fingers fucking into her. It’s all done with complete assuredness, like they’ve done it dozens of times before, for years now maybe, like they know each other’s bodies as well as their own. Were the image in front of him not so filthy, he’d think it was sweet.

He becomes painfully and unfortunately aware of the situation in his pants. It’s just a physical reaction, he tells himself for all of about thirty seconds before his hand dips into his boxers and grasps his cock. If he jerks off to the sight of his little sister and her best friend, there will be no redemption for him. No saving him from this hot, awful hell he’s found himself in. Yet his hand continues its path, and when Clarke’s hips finally lift off the bed and she stifles a scream, coming harder than Bellamy has ever been able to make a woman come, he nearly loses it himself, grips the base of his dick and takes a deep breath. There’s no stopping this — he’s seeing it through to the end now, to make sure Octavia is at the very least being a responsible domme.   
  
She turns off the vibrator and unties Clarke, but doesn’t take the underwear out. She sits at the edge of the bed and kisses Clarke’s wrists, a surprisingly mature and affectionate gesture.   
  
In all of this, he should have picked up on it sooner. He was so appalled by the sex that he didn’t see the bigger, far more important picture: they’re in love.   
  
Just as the thought enters his head, Octavia stands from the bed and stares the cam right in the eye. His heart begins to pound, and he slips his hand out of his pants, almost turns off the iPad and runs into the room to explain, but then Octavia takes the teddy bear off the shelf and says to it, “I don’t remember you,” which is such an adorable, Octavia thing to do. He doesn’t need the reminder that this girl, this bizarrely romantic teen dominatrix, is still his goofy sister with an intense sentimental attachment to her stuffed animals.   
  
The cam points to Clarke on the bed, who has sat up, but hasn’t taken the gag out of her mouth.   
  
“Do you remember this guy?” Octavia asks, off-screen.  
  
Clarke shakes her head.   
  
“Oh god, sorry,” Octavia says, and her arm reaches out to pull the underwear from Clarke’s mouth. Clarke smiles happily at her but still doesn’t speak, and Octavia bends down and kisses her. The teddy bear has been discarded on the bed, so Bellamy can only see torsos and a bit of leg.   
  
“I love you so much,” Octavia says.  
  
“I love you too,” Clarke replies. They kiss some more, and she adds, “Since you don’t have a personal attachment to that teddy bear, can I…”  
  
“Not everything is a sex toy.”  
  
“It is if you try hard enough.”  
  
“Fine, but I get to watch.”  
  
“It’s no fun if you don’t.”  
  
A series of jerky movements disorient the frame, until the camera settles toward the ceiling.   
  
“Oh god,” Bellamy says, but he can’t look away.

“This is how I learned to get myself off,” Clarke says as she straddles the teddy bear. She must have slipped off her underwear in all the movement. Bellamy has an eyeful of her wet, red cunt, dusted with bright blonde hair, which disappears as she lowers herself, and now he’s left with the view of her small pouch of baby fat on her stomach and the bottom of her breasts. The whole picture warbles as she starts humping the teddy bear, and Bellamy’s hand immediately returns to his boxers.   
  
Octavia is in the picture now too, her sports bra finally discarded. He’s surprised to find she actually does have tits, albeit small ones, little cones on her chest that Clarke sucks on while humping the teddy bear faster.   
  
“Does that really feel good?” Octavia asks.  
  
“Yeah,” Clarke says, breathless. “You have to find the right angle.”  
  
“Let me try.”  
  
The camera shakes again and now Bellamy is ferociously fisting his cock and staring straight into his baby sister’s cunt, which doesn’t even have hair on it yet. Octavia humps the teddy bear fast and hard like she’s trying to dominate it, too, and he can hear the vibrator click on while Clarke, presumably, sets it against Octavia’s clit.   
  
“Oh fuck,” Octavia says. “Fuck, you’re right.”  
  
He tacks the word ‘fuck’ onto the list of things they need to talk about, but the thought is soon banished from his mind as he notices if he lies down flat and raises the iPad, moves his fist in sync with her thrusts, it looks and feels like Octavia is fucking him. When Clarke comes into the frame and kisses her, he imagines her straddling him, too, the two of them using his body however they like, experimenting on him the way they do on each other. Loving him, the way they love each other, in a way no one has ever loved him.   
  
It’s a combination of seething envy, the cry signaling Octavia’s climax, and the thought that soon, he plans to bust down their door and catch them in the act, that pushes him over the edge. He bites his arm to keep from making noise, and comes harder than he ever has in his life, and probably ever will again.  
  
“Shit,” Octavia says, which irks him. "He probably heard that.” The teddy bear gets turned face down onto the bed, so he can no longer see anything, only hear the mad dash for pajamas. He wipes his hand off with a tissue, gets up, marches into the hallway, and doesn’t bother knocking before opening their bedroom door.  
  
Clarke has one of Octavia’s soccer shirts on, and is stepping into a pair of shorts. Octavia is settling her bra over her chest, a pair of track pants on her legs. They both freeze, staring at him with wide, afraid and guilty eyes, respectively.   
  
“Is everything okay in here?” he asks.  
  
Octavia picks up the teddy bear and chucks it at his head. “Get out!”  
  
He catches it. Clarke is giving Octavia a shocked look, as if to say, _Did you really just do that?_ The teddy bear smells like pussy. He’s not giving it back.  
  
He came in here planning to confront them, to get this over with. But then he imagines what they'd do if he didn't. Fall asleep holding each other, the one night a week they’re allowed. Wake up together harboring the sanctity of their secret. Live in their little bubble of bliss one more day. He can give them that, even if he'll never have it himself.   
  
He points to his necktie on the pillow and asks, “Is that my tie?”

**Author's Note:**

> Monsterforker on twitter and tumblr.


End file.
